Thank you very much for the useful explanation!
Maybe, considering all the sddm and further changes, it would be better going for a fresh install.
I think it would be best to reinstall after this qt transition is over, so that I can install packages without any trouble: is there some rough timeline available about this?
Also, when qt transition is over I would happily come to IRC to fetch the latest KDE flavour, anyway, just for the sake of curiosity, is there a plan about when next release should be due?
THX